JP2000168012A - Ink image receiving layer easy-adhesive polyester film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink image receiving layer easy-adhesive polyester film excellent in concealability and also excellent in the adhesiveness to an aq. ink image receiving layer of an ink jet printer and water-resistant adhesiveness as ink image receiving paper. SOLUTION: In a film wherein a coating film is laminated to at least the single surface of a polyester film, the coating film consists of 50-80 wt.% of (A) copolyester wherein a ratio of a dicarboxylic acid component having a sulfonate base to all of carboxylic acid components is 1-16 mol% and a secondary transition point is 20-90 deg.C, 10-30 wt.% of (B) carboxylic acid modified polyvinyl alcohol, 3-25 wt.% of (C) fine particles with a particle size of 20-80 nm and 1-20 wt.% of (D) a crosslinking agent and the surface energy of the coating film is 50-65 dyne/cm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester film having an ink-receiving layer, which is easy to adhere to, and more particularly, to an image-receiving paper excellent in concealing property and excellent in adhesion to water-based ink-receiving layers such as ink jet printers, and water resistance. The present invention relates to an ink-receiving layer easy-adhesion polyester film useful for an ink-receiving layer.

[0002]

2. Description of the Related Art A polyester film represented by a polyethylene terephthalate film has been widely used as a base film of a film for an image receiving paper.
In recent years, with the demand for color printers, new printing methods such as an ink jet method have been developed. An image receiving paper film for such a printing method is disclosed in JP-A-64-364.
No. 79 and Japanese Patent Application Laid-Open No. 1-95091, it is necessary to form an ink image receiving layer on a film. As the ink image receiving layer, a porous material having good ink absorbability is used, but the ink image receiving layer has poor adhesion to a polyester film used as a base film.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink-receiving layer having excellent adhesiveness and concealing properties.
An object of the present invention is to provide an ink-receiving layer easy-adhesion polyester film useful for an image-receiving paper for an ink-jet printer.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
According to the present invention, there is provided a film obtained by laminating a coating film on at least one surface of a polyester film, wherein the coating film has (A) a ratio of 1 to 16 mol of a dicarboxylic acid component having a sulfonic acid group to all carboxylic acid components. % Copolyester 50 having a secondary transition point of 20 to 90 ° C.
To 80% by weight, (B) 10 to 30% by weight of carboxylic acid-modified polyvinyl alcohol, (C) average particle size of 20 to 80 n
m of fine particles of 3 to 25% by weight and (D) 1 to 20% by weight of a crosslinking agent, and the surface energy of the coating film is 50 to 65 d.
yne / cm.

(Polyester Film) The polyester constituting the polyester film in the present invention includes, for example, an aromatic dicarboxylic acid component such as terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, and 4,4'-diphenyl dicarboxylic acid. For example, a polyester composed of a glycol component such as ethylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, and 1,6-hexanediol is preferable,
Especially polyethylene terephthalate, polyethylene-2
6-Naphthalene dicarboxylate is preferred. Also,
Copolymerized polyester such as the above components may be used.

If necessary, organic or inorganic fine particles as a lubricant may be added to the polyester to improve the winding property when producing a film and the transportability of the film when applying an ink image receiving layer and the like. It is preferable to contain. Examples of such fine particles include calcium carbonate, calcium oxide, aluminum oxide, kaolin, silicon oxide, zinc oxide, crosslinked acrylic resin particles, crosslinked polystyrene resin particles, urea resin particles, melamine resin particles, crosslinked silicone resin particles, and the like. Also, besides fine particles, colorants, antistatic agents, antioxidants, lubricants, catalysts, polyethylene, polypropylene, ethylene-propylene-polymer, other resins such as olefinic ionomers, etc., as long as the transparency is not impaired. It can be arbitrarily contained.

It is preferable to use a polyester film (white polyester film) having a gloss of 60 ° or more, a light transmittance of 20% or less and a white color for the polyester film in the present invention. This white polyester film is obtained by adding a white pigment such as titanium oxide and / or barium sulfate to polyester, for example, for 5 to 5 hours.
It can be obtained by containing 20% by weight. In addition, the white polyester film preferably has a gloss of 60 or more than the sharpness of the printed matter when used as an image receiving paper, and has a light transmittance of 20% or less from the design of the printed matter. .

The polyester film of the present invention comprises:
A biaxially stretched film having a heat shrinkage of 1% or less when held at 150 ° C. for 30 minutes has good dimensional stability when a polyester film is used as an image receiving paper, and suppresses printing misalignment and the like. It is preferable because it is possible. A biaxially stretched film having such a heat shrinkage is obtained by, for example, setting the film density to 1.390 g / cm ³ or more by heat setting or heat treatment at a temperature of Tg or more of polyester after biaxial stretching. be able to.

(Coating film) In the present invention, a coating film containing (A) a copolyester, (B) a carboxylic acid-modified polyvinyl alcohol, (C) fine particles and (D) a crosslinking agent as main components is laminated on a polyester film. .

The (A) copolyester used as a component for forming this coating film is a polyester in which the ratio of a dicarboxylic acid component having a sulfonic acid group to the total dicarboxylic acid components in the molecule is 1 to 16 mol%. . Such copolyesters include terephthalic acid, isophthalic acid, 2,2
Carboxylic acid components such as 6-naphthalenedicarboxylic acid, hexahydroterephthalic acid, 4,4'-diphenyldicarboxylic acid, phenylindanedicarboxylic acid, adipic acid, sebacic acid, 5-sulfoisophthalic acid, trimellitic acid, dimethylolpropionic acid And a dicarboxylic acid component having a sulfonic acid group such as 5-Na sulfoisophthalic acid, 5-K sulfoisophthalic acid, or 5-K sulfoterephthalic acid, and ethylene glycol, diethylene glycol, neopentylene glycol, 1,4-butanediol, 1,6
Polyester composed of -hexanediol, 1,4-cyclohexanedimethanol, glycerin, trimethylolpropane, and a hydroxy compound component such as an alkylene oxide adduct of bisphenol-A, as an aqueous solution, aqueous dispersion or emulsion. used.

In the copolyester (A), the dicarboxylic acid component having a sulfonic acid group for imparting hydrophilicity is present in an amount of 1 to 16 mol% based on all carboxylic acid components in the molecule.
, But is preferably 1.5 to 14 mol%. If the content of the dicarboxylic acid component having a sulfonic acid salt group is less than 1 mol%, the hydrophilicity of the copolyester is insufficient.
If it exceeds 6 mol%, the moisture resistance of the coating film is undesirably reduced.

The (A) copolyester must have a secondary transition point (Tg) of 20 to 90 ° C. Tg is 20
If the temperature is lower than 90 ° C., the film tends to block, while
It is not preferable that the temperature be higher than 0 ° C., since the abrasion and the adhesiveness of the film decrease.

[0013] The carboxylic acid-modified polyvinyl alcohol (B) used as a component for forming the coating film must have a saponification degree of 74 to 90 mol%. If the saponification degree is less than 74 mol%, the moisture resistance of the coating film is reduced, while if it exceeds 90 mol%, the adhesion to the ink image receiving layer is undesirably reduced.

The fine particles (C) used as components for forming the coating film are organic or inorganic fine particles having a particle size of 2%.
It is of 0 to 80 nm. Such fine particles include calcium carbonate, calcium oxide, aluminum oxide, kaolin, silicon oxide, zinc oxide, crosslinked acrylic resin particles,
Examples include crosslinked polystyrene resin particles, melamine resin particles, crosslinked silicone resin particles, and the like. When the particle size of the fine particles is 2
If the thickness is less than 0 nm, the film is likely to be blocked, while if it exceeds 80 nm, the shaving property is undesirably reduced.

Further, as the crosslinking agent (D) used as a component for forming the coating film, there are oxazoline group-containing polymers, urea resins, melamine resins, epoxy resins and the like.

The oxazoline group-containing polymer used in the present invention is disclosed in JP-B-63-48884,
Polymers described in JP-A-60941, JP-A-2-99537, and the like, or polymers similar thereto.

Specific examples include an addition-polymerizable oxazoline (a) represented by the following general formula (I) and a polymer obtained by polymerizing another monomer (b) if necessary.

[0018]

Embedded image

(However, R ¹ , R ² , R ³ and R ⁴ in the formula (I) each represent a substituent selected from hydrogen, halogen, an alkyl group, an aralkyl group, a phenyl group and a substituted phenyl group. , R ⁵ represents an acyclic organic group having an addition-polymerizable unsaturated bond group.)

Specific examples of the addition-polymerizable oxazoline (a) include 2-vinyl-2-oxazoline and 2-vinyl-
4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-methyl -2-oxazoline and the like.
Mixtures of more than one species can be used. Of these,
2-Isopropenyl-2-oxazoline is readily available industrially and is preferred.

The monomer (b) other than the addition-polymerizable oxazoline is not particularly limited as long as it is a monomer copolymerizable with the addition-polymerizable oxazoline (a). For example, methyl acrylate, methyl methacrylate, Acrylic esters such as butyl acrylate and butyl methacrylate, unsaturated carboxylic acids such as acrylic acid, methacrylic acid and itaconic acid, unsaturated nitriles such as acrylonitrile and methacrylonitrile, acrylamide, methacrylamide and N-methylolacrylamide , Unsaturated amides such as N-methylol methacrylamide, vinyl esters such as vinyl acetate and vinyl propionate, vinyl ethers such as methyl vinyl ether and ethyl vinyl ether, α-olefins such as ethylene and propylene, and vinyl chloride. Halogen-containing α, β-unsaturated monomers such as vinylidene chloride and vinyl fluoride, α, β-unsaturated aromatic monomers such as styrene and α-methylstyrene, and the like. Mixtures of two or more can be used.

In order to obtain a polymer using the addition-polymerizable oxazoline (a) and, if necessary, at least one other monomer (b), polymerization can be carried out by a conventionally known polymerization method. For example, various methods such as an emulsion polymerization method (a method of collectively mixing and polymerizing a polymerization catalyst, water, a surfactant, and a monomer), a monomer dropping method, a multistage polymerization method, and a pre-emulsion method can be employed.

Conventionally known polymerization catalysts can be used. For example, ordinary radical polymerization initiators such as hydrogen peroxide, potassium persulfate, and 2,2′-azobis (2-aminodipropane) dihydrochloride can be exemplified.

Examples of the surfactant include conventionally known anionic, nonionic, cationic and amphoteric surfactants and reactive surfactants.

The polymerization temperature is usually from 0 to 100 ° C., preferably from 50 to 80 ° C., and the polymerization time is usually from 1 to 1
0 hours.

When a polymer is obtained using the addition-polymerizable oxazoline (a) and at least one other monomer (b), the amount of the addition-polymerizable oxazoline (a) is 0.5 It is preferable to determine it appropriately in the range of not less than weight%. If the amount of the addition-polymerizable oxazoline (a) is less than 0.5% by weight, it may be difficult to achieve the object of the present invention.

Specific examples of the epoxy resin include polyepoxy compounds, diepoxy compounds and monoepoxy compounds. Examples of polyepoxy compounds include sorbitol, polyglycidyl ether, polyglycerol polyglycidyl ether, and pentaerythritol Examples of polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanate, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, and diepoxy compounds include neopentyl glycol diglycidyl ether, 1,6- Hexanediol diglycidyl ether, resorcin diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol Call diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, as a monoepoxy compound such as allyl glycidyl ether, 2-
Ethylhexyl glycidyl ether, phenyl glycidyl ether and the like can be mentioned.

Examples of the urea resin include dimethylol urea, dimethylol ethylene urea, dimethylol propylene urea, tetramethylol acetylene urea, and 4-methoxy 5-dimethylpropylene urea dimethylol.

As the melamine resin, a compound obtained by reacting a methylol melamine derivative obtained by condensing melamine and formaldehyde with methyl alcohol, ethyl alcohol, isopropyl alcohol or the like as a lower alcohol, and a mixture thereof are preferable.
Examples of the methylol melamine derivative include monomethylol melamine, dimethylol melamine, trimethylol melamine, tetramethylol melamine, pentamethylol melamine, and hexamethylol melamine.

Particularly preferred are oxazoline group-containing polymers. These crosslinking agents may be used alone or in combination of two or more in some cases.

In the present invention, (A) a copolyester,
The mixing ratio of (B) the carboxylic acid-modified polyvinyl alcohol, (C) fine particles and (D) the crosslinking agent is (A) 50 to 80% by weight of a copolyester, (B) 10 to 30% by weight of a carboxylic acid-modified polyvinyl alcohol, C) Fine particles 3 to 35
% By weight, and (D) 1 to 20% by weight of a crosslinking agent. If the proportion of the component (A) is less than 50% by weight, the adhesion to the polyester film is insufficient, while if it exceeds 80% by weight, the adhesion to the ink image receiving layer is undesirably reduced. If the proportion of the component (B) is less than 10% by weight, the adhesion to the ink image-receiving layer will be insufficient, while if it exceeds 30% by weight, the blocking resistance will be undesirably reduced. If the proportion of the component (C) is less than 3% by weight, the lubricity (transportability) of the film is insufficient. On the other hand, if it exceeds 25% by weight, the shaving property is undesirably reduced. If the proportion of the component (D) is less than 1% by weight, water resistance and blocking properties are insufficient, and if it exceeds 20% by weight, the adhesion to the ink image receiving layer is undesirably reduced.

The surface energy of the coating film in the present invention needs to be 50 to 65 dyne / cm, particularly preferably 55 to 62 dyne / cm. When the surface energy is less than 50 dyne / cm, the coating properties and adhesiveness of the aqueous ink image-receiving layer become poor. When the surface energy exceeds 65 dyne / cm, the adhesion to the polyester film as a substrate becomes insufficient, It is not preferable because moisture resistance may be insufficient.

The surface energy is 50 to 65 dyne / c
m is a coating film in which (A) a copolyester, (B) a water-soluble polymer, (C) fine particles and (D) a crosslinking agent fall within the range of the present invention, for example, a thickness of 0.02 to 1 μm. Can be obtained.

In the polyester film of the present invention, the center line average roughness (Ra) of the coating film surface is in the range of 10 nm to 250 nm, and the adhesiveness between the coating film and the polyester film can be improved. It is preferable because the adhesion between the coating film and the ink image receiving layer, the abrasion resistance of the coating film, and the blocking resistance and transportability of the laminated film are improved. Such R
The coating film having a can be obtained, for example, by using the fine particles in the above-mentioned ratio as a coating film component.

In the present invention, in addition to the above-mentioned components, an antistatic agent, a coloring agent, a surfactant, an ultraviolet absorber and the like can be used as components for forming a coating film.

(Lamination of Coating Film) In the present invention, a coating film composed of the above components is laminated on at least one side of the polyester film. For example, an aqueous liquid containing a component for forming a coating film is applied to a stretchable polyester film. After that, drying, stretching and, if necessary, heat treatment can be performed to laminate. The solid concentration of this aqueous liquid is usually 30
% By weight or less, more preferably 10% by weight or less.

The stretchable polyester film is an unstretched polyester film, a uniaxially stretched polyester film or a biaxially stretched polyester film.
Among them, a vertically stretched polyester film uniaxially stretched in a film extrusion direction (longitudinal direction) is particularly preferable.

When the aqueous liquid is applied to the polyester film, if it is carried out in a normal application step, that is, in a step separated from the production step of the film in the biaxially stretched and heat-set polyester film, trash, dust and the like are easily entrained. Not preferred. From such a viewpoint, application in a clean atmosphere, that is, application in a film manufacturing process is preferable. According to this coating, the adhesion of the coating film to the polyester film is further improved.

As a coating method, any known coating method can be applied. For example, a roll coating method, a gravure coating method, a roll brushing method, a spray coating method, an air knife coating method, an impregnation method, a curtain coating method and the like can be used alone or in combination. The amount of coating is 0.5 to 20 g / m2 of running film,
10 g is preferred. The aqueous liquid is preferably used as an aqueous dispersion or an emulsion.

The stretchable polyester film coated with the aqueous liquid is guided to a drying and stretching treatment step, and such treatment can be performed under conditions conventionally accumulated in the art. As preferable conditions, for example, the drying condition is 90.
130 ° C. × 2 to 10 seconds, and the stretching temperature is 90 to 13
0 ° C., the stretching ratio is 3 to 5 times in the machine direction, 3 to 5 times in the transverse direction, and 1 to 3 times in the machine direction if necessary.
80 to 240 ° C. × 2 to 20 seconds.

The thickness of the polyester film after such treatment is preferably 50 to 150 μm, and the thickness of the coating film is preferably 0.02 to 1 μm.

[0042]

The present invention will be further described with reference to the following examples.
In addition, each characteristic value was measured by the following method.

1. Adhesiveness 30% by weight of spherical silica (average particle diameter 18μ, average pore diameter 200 angstrom, average pore volume 1.5cc / g) 30% by weight and polyvinyl alcohol (Kuraray PVA117) 70% by weight are mixed with the coating surface of the polyester film. The obtained aqueous slurry was applied in a dry thickness of 20 μm, and a width of 1 μm was applied thereon.
A 2.7 mm, 150 mm long scotch tape (No. 600, manufactured by 3M Co.) was adhered so as to prevent air bubbles from entering, and the top of the scotch tape was adhered by a manual load roll described in JIS C2701 (1975). Later, cut out to tape width. When the scotch tape was peeled from the sample thus prepared, the state of peeling of the ink image receiving layer from the polyester film was observed, and the adhesion was evaluated as follows. A: No peeling was observed at all and good adhesion B: Slight peeling was observed at the foreign matter portion C: Peeling was noticeably observed

2. Water-Resistant Adhesion The grease was impregnated with water from above the ink image-receiving layer, rubbed, and the number of rubbings before the ink-image-receiving layer was dropped was evaluated as described below. A: 50 times or more: extremely good water-resistant adhesiveness B: 30 to 50 times: good water-resistant adhesiveness C: less than 30 times: poor water-resistant adhesiveness

3. Coefficient of friction According to ASTM D 1894-63, a static friction coefficient was measured by applying a load of 1 kg with the front and back surfaces of the film together using a slipper measuring device manufactured by Toyo Tester Co., Ltd. If the coefficient of friction exceeds 0.6, film transportability will be impaired.

4. Blocking property Two films cut to a width of 50 mm are piled up, and 50 kg /
After treatment at 40 ° C. × 50% RH × 17 hours under a load of cm ² , the peel strength (g
/ 50 mm). Evaluation was made as follows by the value of the peel strength. Peel strength ≦ 10 g / 50 mm: good blocking property 10 g / 50 mm <peel strength ≦ 30 g / 50 mm—somewhat good blocking property 30 g / 50 mm <peel strength: poor blocking property

5. Surface energy WA Zisman: “Contact Augle, Wettability and Adh
esion ", Am. Chem. Soc., (1964), the measured critical surface tension γc was used as the surface energy.

6 Secondary transition point Measured at a heating rate of 20 ° C./min with a Thermal Analyst 2000 type differential calorimeter manufactured by DuPont.

7. Intrinsic viscosity The viscosity of the solution with orthochlorophenol solvent is 35 ℃
Was measured and determined.

8. Water dispersibility The coating agent was diluted with water to form a 0.2% by weight aqueous dispersion, and the light transmittance was measured using a quartz cell with a double beam spectrophotometer (type 228A) manufactured by Hitachi, Ltd. . Evaluation was made as follows from the measurement results. Light transmittance ≧ 50% good water dispersibility 50%> light transmittance ≧ 30% slightly good water dispersibility 30%> light transmittance poor water dispersibility

9. Moisture resistance In the evaluation of the blocking property, the treatment condition was 60 ° C.
Peeling strength (g / 50 mm) was measured in the same manner except that x70% RH x 17 hours. Evaluation was made as follows from the measurement results. Peel strength ≦ 10 g / 50 mm: good moisture resistance 10 g / 50 mm <peel strength ≦ 30 g / 50 mm—somewhat good moisture resistance 30 g / 50 mm ≦ peel strength: poor moisture resistance

10. Gloss Gs (60 °) Gloss is measured according to JIS Z 8741-1962 using a gloss meter GM-3D manufactured by Murakami Color Research Laboratory.
The measurement angle is 60 °, the number of measurements is n = 5, and the average value is the value of the gloss Gs (60 °).

11. Light transmittance The light transmittance was measured using a HR-100 haze meter manufactured by Murakami Color Research Laboratory in accordance with ASTM D1003.

12. Heat Shrinkage The shrinkage after heat treatment of the polyester film at 150 ° C. for 30 minutes was measured at a distance between the gauge points of 30 cm.

13. Center line average roughness (Ra) According to JIS B0601, using a high-precision surface roughness meter SE-3FAT manufactured by Kosaka Laboratory Co., Ltd.
μm, load 30 mg, magnification 50,000 times, cutoff 0.
Under the condition of 08 mm, a portion of the measured length L is drawn from the surface roughness curve in the direction of its center line under the condition of 08 mm, and the center line of the drawn portion is set as the X axis, and the direction of the longitudinal magnification is set as the Y axis. When the roughness curve was represented by Y = f (x), the value given by the following equation was represented in nm.

[0056]

(Equation 1)

In this measurement, the reference length is 1.25 mm, and
Four samples were measured and represented by an average value.

14. Sharpness The polyester film coated with the ink image-receiving layer was printed on an inkjet printer (PM-PM manufactured by EPSON).
At 750C), the design drafting created by CAD such as a personal computer was printed, and the sharpness of the printed matter was visually observed and evaluated as follows. A: Very good clarity ... very good clarity B: Good clarity ... good clarity C: Poor clarity ... Poor clarity

Example 1 A polyester (intrinsic viscosity: 0.62) comprising a terephthalic acid component and an ethylene glycol component was melt-extruded onto a rotating cooling drum maintained at 20 ° C. to obtain an unstretched film. After stretching the stretched film 3.6 times in the machine axis direction, the acid component is terephthalic acid [60 mol%], isophthalic acid [36 mol%] and 5-Na sulfoisophthalic acid [4 mol%], and the glycol component is ethylene. Copolyester consisting of glycol [60 mol%] and neopentyl glycol [40 mol%] (Tg = 30 ° C., hereinafter simply referred to as [E])
55% by weight, saponification degree 74 to 80 mol% Carboxylic acid-modified polyvinyl alcohol 16% by weight, average particle size 40 nm
10% by weight of crosslinked acrylic resin particles of 2-propenyl-
An aqueous liquid having a solids concentration of 4% by weight and having a composition comprising 10% by weight of an oxazoline (60% by mole) and methyl methacrylate (40% by mole) copolymer and 9% by weight of polyoxyethylene lauryl ether was applied by a roll coater. .

Next, the longitudinally stretched film coated with the aqueous liquid was stretched 4 times in the transverse direction while drying, and further heat-set at 230 ° C. to obtain a biaxially stretched film having a thickness of 100 μm.

The film thickness of this film is 0.03 μm.
m, the center line average surface roughness was 23 nm, the surface energy was 60 dyne / cm, and the heat shrinkage was 0.9% in the vertical direction and 0.2% in the horizontal direction. Table 1 shows the characteristics of this film.

[Comparative Example 1] Except that the aqueous liquid was not applied,
Table 1 shows the properties of the biaxially stretched polyester film obtained in the same manner as in Example 1.

Examples 2 to 10 Biaxially stretched polyester films were obtained in the same manner as in Example 1 except that the types and ratios of the coating agents were changed as shown in Table 1. Table 1 shows the characteristics of this film.

[0064]

[Table 1]

As is evident from the results shown in Table 1, the polyester film having good adhesion to the ink image-receiving layer of the present invention is excellent in adhesiveness. In Table 1, types E and F (Note 1) of the copolyester indicate that they are the following copolymers. E: Terephthalic acid [60 mol%] / isophthalic acid [36
Mol%] · 5-Na sulfoisophthalic acid [4 mol%] /
Copolymer of ethylene glycol [60 mol%] / neopentyl glycol [40 mol%] (Tg = 30 ° C.) F: 2,6-naphthalene dicarboxylic acid [20 mol%]
Isophthalic acid [76 mol%] 5-K sulfoterephthalic acid [4 mol%] / ethylene glycol [50 mol%]
Neopentyl glycol [50 mol%] copolymer (Tg
= 42 ° C)

In Table 1, the carboxylic acid-modified polyvinyl alcohol and the types P, Q,
R and S (Note 2) indicate the following compounds. P: carboxylic acid-modified polyvinyl alcohol having a saponification degree of 74 to 80 mol% Q: carboxylic acid-modified polyvinyl alcohol having a saponification degree of 85 to 90 mol% R: polyvinyl alcohol having a saponification degree of 76 to 82 mol% S: saponification degree 86 to 89 mol % Polyvinyl alcohol

In Table 1, the types M and N (Note 3) of the fine particles indicate the following compounds. M: Crosslinked acrylic particles having an average particle size of 40 nm N: Colloidal silica particles having an average particle size of 80 nm

In Table 1, types of crosslinking agents T, U and X
(Note 4) indicates the following compounds. T: polymer having an oxazoline group: 2-propenyl-
Oxazoline (60 mol%) and methyl methacrylate (40 mol%) copolymer U: melamine resin: trimethylol melamine X: epoxy resin: polyglycerol polyglycidyl ether

[Examples 11 to 14 and Comparative Examples 2, 3]
(A) A biaxially stretched polyester film was obtained in the same manner as in Example 1, except that the types of copolyester were changed as shown in Tables 2 and 3, except that copolyesters having different Tg were used. Table 2 shows the properties of the obtained film.

[0070]

[Table 2]

[0071]

[Table 3]

As is evident from the results shown in Table 2, the polyester film having good adhesion to the ink image-receiving layer of the present invention is excellent in blocking resistance and adhesiveness.

Examples 15 to 19 and Comparative Examples 4 and 5
(A) A biaxially stretched polyester film was obtained in the same manner as in Example 1, except that the proportion of the dicarboxylic acid component containing a sulfonic acid group in the copolyester was changed as shown in Table 4. Table 4 shows the properties of the obtained film.

[0074]

[Table 4]

As is evident from the results shown in Table 4, the coating composition of the present invention is excellent in water dispersibility, and the polyester film of the present invention having excellent adhesion to an ink image receiving layer is excellent in moisture resistance.

[Examples 20 to 22 and Comparative Examples 6 to 11]
Biaxial in the same manner as in Example 1 except that the ratios of (A) copolyester, (B) carboxylic acid-modified polyvinyl alcohol, polyvinyl alcohol, (C) fine particles, and (D) crosslinking agent were changed as shown in Table 5. A stretched polyester film was obtained. Table 5 shows the properties of the obtained film.

[0077]

[Table 5]

As is evident from the results shown in Table 5, the polyester film having good adhesion to the ink receiving layer of the present invention is excellent in adhesiveness and transportability.

[Examples 23 and 24 and Comparative Examples 12 and 1
3] (C) A biaxially stretched polyester film was obtained in the same manner as in Example 1, except that the particle size of the fine particles was changed as shown in Table 6. Table 6 shows the properties of the obtained film.

[0080]

[Table 6]

As is evident from the results shown in Table 6, the polyester film having good adhesion to the ink image-receiving layer of the present invention has excellent blocking resistance.

[Examples 25 and 26 and Comparative Examples 14 and 1
5] Biaxial stretching in the same manner as in Example 1 except that the ratio of (A) copolyester, (B) carboxylic acid-modified polyvinyl alcohol, (C) fine particles, and (D) the crosslinking agent was changed as shown in Table 7. A polyester film was obtained. Table 7 shows the properties of the obtained film.

[0083]

[Table 7]

As is evident from the results shown in Table 7, the polyester film having good adhesion to the ink image-receiving layer of the present invention is excellent in adhesiveness and transportability.

[Examples 27 to 29 and Comparative Examples 16 to 1]
8] Biaxially stretched polyester in the same manner as in Example 1 except that the ratios of (A) copolyester, (B) carboxylic acid-modified polyvinyl alcohol (C) fine particles and (D) crosslinking agent were changed as shown in Table 8. I got a film. Table 8 shows the properties of the obtained film.

[0086]

[Table 8]

As is evident from the results shown in Table 8, the polyester film easily adhered to the ink image-receiving layer of the present invention is excellent in adhesiveness and transportability.

Example 30 A composition comprising 90% by weight of a polyester (intrinsic viscosity: 0.62) comprising a terephthalic acid component and an ethylene glycol component and 10% by weight of titanium oxide was placed on a rotary cooling drum maintained at 20 ° C. After being melt-extruded into an unstretched film, and then stretched 3.6 times in the machine axis direction, the acid components are terephthalic acid [60 mol%], isophthalic acid [36 mol%] and 5-Na Copolyester (Tg = 30 ° C., hereinafter simply referred to as [E]) 55 comprising sulfoisophthalic acid [4 mol%] and a glycol component comprising ethylene glycol [60 mol%] and neopentyl glycol [40 mol%]
% By weight, 16% by weight of carboxylic acid-modified polyvinyl alcohol having a saponification degree of 74 to 80% by mole, 10% by weight of crosslinked acrylic resin particles having an average particle size of 40 nm, 2-propenyl-oxazoline (60% by mole) and methyl methacrylate (40% by mole) %) An aqueous liquid having a solid content of 4% by weight and having a composition comprising 10% by weight of a copolymer and 9% by weight of polyoxyethylene lauryl ether was applied by a roll coater.

Next, the longitudinally stretched film to which the aqueous liquid was applied was stretched 4 times in the transverse direction while drying, and further heat-set at 230 ° C. to obtain a biaxially stretched film having a thickness of 100 μm. The film thickness of this film is 0.03 μm, the center line average surface roughness is 60 nm, the gloss is 68, the light transmittance is 3%, the heat shrinkage is 0.9% in the vertical direction, and 0 in the horizontal direction. .2%, clearness and adhesion were good.

Comparative Example 19 A biaxially stretched polyester film was obtained in the same manner as in Example 30, except that the copolyester of Example 30 was changed to L. The film thickness of this film is 0.03 μm, the average surface roughness is 120 nm, the glossiness is 41, the light transmittance is 3%, and the heat shrinkage is 0 in the vertical direction.
9%, 0.2% in the horizontal direction, poor clarity and poor adhesion.

[0091]

The polyester film having good adhesion to the ink image-receiving layer of the present invention is excellent in concealing property, excellent in adhesion to water-based ink-receiving layers such as ink jet printers, and water-resistant, and is useful for image receiving paper. It is.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Shinji Yano 3-37-19 Koyama, Sagamihara-shi, Kanagawa F-term in Sagamihara Research Center, Teijin Limited 4F100 AK21B AK36B AK41A AK41A AK41B AK53B AK54B AL07B BA02 BA03 BA07 BA10A BA10C BA13 BA16 CA02B CC00B DE01B EH46 EJ38A EJ86 HB31C JA03A JA05B JB05C JB20B JD14 JK14B JK20B JL10A JL11 JN01A JN21A YY00A YY00B 4J002 BC03 CD02 CC03 CD04 CB0043 GA06 GA08 GA13 HA216 HA286 HA526 KA03 KA20 MA13 NA06 NA07 PC08

Claims (8)

[Claims] 1. A film in which a coating film is laminated on at least one surface of a polyester film, wherein the coating film has a ratio of 1 to 16 mol of a dicarboxylic acid component having a sulfonate group to (A) all carboxylic acid components. %
And a copolyester 5 having a secondary transition point of 20 to 90 ° C.
0-80% by weight, (B) 10-30% by weight of carboxylic acid-modified polyvinyl alcohol, (C) average particle size of 20-80.
3 to 25% by weight of fine particles having a diameter of 3 nm and (D) a crosslinking agent 1 to 20
% By weight, and the surface energy of the coating film is 50 to 65%.
dyne / cm, an easily adherent polyester film for the ink image receiving layer. 2. The polyester film according to claim 1, wherein (D) the crosslinking agent is at least one selected from the group consisting of oxazoline-containing polymers, urea resins, melamine resins and epoxy resins. 3. The polyester film according to claim 1, wherein (B) the carboxylic acid-modified polyvinyl alcohol has a saponification degree of 74 to 90 mol%. 4. The polyester film according to claim 1, wherein the polyester film has a glossiness of 60 or more, a light transmittance of 20% or less, and is white. 5. A polyester film having a viscosity of 3 ° C. at 150 ° C.
2. The polyester film according to claim 1, which is a biaxially stretched film having a heat shrinkage of 1% or less when held for 0 minutes. 6. A coating film having a center line average roughness Ra of 10
The polyester film according to claim 4, wherein the thickness of the polyester film is in the range of nm to 250 nm. 7. The ink image receiving layer according to claim 4, wherein the polyester film has a glossiness of 60 or more, a light transmittance of 20% or less, and is white, and further comprises an aqueous ink image receiving layer on the coating film. Adhesive polyester film. 8. The polyester film according to claim 7, which is used for an image receiving paper for an ink jet printer.